KR102312874B1 - Method for detecting zigbee in heterogeneous wireless network and zigbee apparatus - Google Patents

Abstract

It relates to a ZigBee receiving device in a heterogeneous wireless network. According to an embodiment, the ZigBee receiving device includes a channel state evaluator that evaluates a channel state based on RSSI in a wakeup state, and a ZigBee signature that checks whether a ZigBee signature exists in a signal received in a wakeup state It may include a check unit and a duty cycle control unit for switching to a next state based on at least one of a channel state and the existence of a ZigBee signature.

Description

ZigBee detection method and ZigBee device in heterogeneous wireless networks

The present invention relates to a ZigBee detection method and a ZigBee device in a heterogeneous wireless network, and more particularly, to a technology for efficiently reducing power consumption in a heterogeneous wireless network interference environment.

In recent home networks, a ZigBee network for short-distance communication is widely used. The ZigBee network is a communication technology that consumes less power and is implemented relatively inexpensively compared to other wireless communication technologies. Due to these characteristics, the ZigBee network is being used in various fields such as industry, science, and medicine.

The physical (PHY) layer and the medium access control (MAC) layer of the ZigBee network are defined by the IEEE 802.15.4 standard. The 2.4 GHz ISM (Industrial, Science, and Medical) band, defined in the physical layer of IEEE 802.15.4, is an unlicensed frequency band widely used in industry, science, and medicine. are using In particular, as the use of wireless LANs increases due to the spread of smartphones and tablet PCs, it causes a lot of interference in ZigBee networks using the same frequency band. Since the ZigBee network has a small transmission output, it is greatly affected by interference by a wireless LAN with a relatively large transmission output. Interference by heterogeneous networks causes transmission failure in ZigBee networks and has a fatal impact on energy efficiency.

A ZigBee detection method and a ZigBee apparatus are provided for efficiently reducing power consumption due to interference of heterogeneous wireless devices in a heterogeneous wireless network environment.

According to an aspect, a ZigBee transmission apparatus in a heterogeneous wireless network includes a packet generator that generates a data packet by inserting a predefined ZigBee signature based on the interference strength of a nearby heterogeneous wireless device, and transmits the generated data packet. It may include a packet transmitter.

According to another aspect, the ZigBee transmission apparatus may further include an interference determination unit that determines whether or not there is interference from a nearby heterogeneous wireless device, and measures the strength of the interference if there is interference.

The packet generator may not insert the ZigBee signature if there is no interference from heterogeneous wireless devices as a result of the determination of the interference determiner.

As a result of the determination of the interference determining unit, if there is interference from heterogeneous wireless devices, the packet generator may determine a size of the ZigBee signature based on the measured interference strength and insert a predefined ZigBee signature corresponding to the determined size.

In this case, the data packet may include a 7-bit ZigBee signature field and a 1-bit dummy field for inserting the ZigBee signature before the preamble.

According to an aspect, a ZigBee receiving device in a heterogeneous wireless network environment includes a channel state evaluator for evaluating a channel state based on RSSI in a wakeup state, and the presence of a ZigBee signature in a signal received in a wakeup state It may include a ZigBee signature checker for checking whether or not there is, and a duty cycle controller for controlling a transition to a next state based on at least one of a channel state and the existence of a ZigBee signature.

The ZigBee signature checker may calculate a correlation value for a sequence of predetermined bits and a predefined sequence of signal samples in the received signal, and check whether a ZigBee signature exists based on the calculated correlation value.

The duty cycle controller may control to switch to a listening state when the channel state is a busy state and a ZigBee signature exists, and to switch to a sleep state otherwise.

The duty cycle controller may control to switch to the listening state when the channel state is the busy state when there is no interference from the neighboring heterogeneous wireless devices.

In this case, the ZigBee signature is composed of a pseudo-random noise (PN) sequence of predetermined bits, and may be inserted into a previously reserved field in front of the preamble signal by the ZigBee transmission device.

In this case, the size of the predetermined bit may have a maximum of 7 bits according to the interference strength of the neighboring heterogeneous wireless devices.

According to an aspect, a method for detecting ZigBee in a heterogeneous wireless network includes converting a ZigBee receiving device to a wakeup state, evaluating a state of a channel based on RSSI in the wakeup state, and ZigBee in a received signal. It may include checking whether a signature exists, and switching to a next state based on at least one of a channel state and a ZigBee signature.

Evaluating the status of the channel includes collecting a series of RSSI samples from the RSSI register and processing the collected series of RSSI samples to evaluate the channel status as idle or busy. can do.

The step of checking the existence of the ZigBee signature includes calculating a correlation value for a predetermined sequence in the received signal and a sequence of predefined signal samples, and determining whether the ZigBee signature exists based on the calculated correlation value. can check

In the step of transitioning to the next state, if the channel state is a busy state and a ZigBee signature exists, it may switch to a listening state, otherwise, it may switch to a sleep state.

The step of switching to the next state may include switching to the listening state when the channel state is a busy state when there is no interference from neighboring heterogeneous wireless devices.

In this case, the ZigBee signature is composed of a pseudo-random noise (PN) sequence of predetermined bits, and may be inserted into a previously reserved field in front of the preamble signal by the ZigBee transmission device.

In this case, the size of the predetermined bit may have a maximum of 7 bits according to the interference strength of heterogeneous wireless devices.

In a heterogeneous wireless network environment, power consumption due to interference of heterogeneous wireless devices can be effectively reduced.

1 illustrates an operation of a general ZigBee system in a heterogeneous wireless network.
2 illustrates an operation of a ZigBee system according to an embodiment in an interference environment of heterogeneous wireless networks.
3 is a block diagram of an apparatus for transmitting ZigBee according to an embodiment.
4 is a block diagram of a ZigBee receiving apparatus according to an embodiment.
5 is a flowchart of a method for generating a ZigBee packet performed by a ZigBee transmission apparatus according to an embodiment.
6 is a flowchart of a ZigBee detection method performed by a ZigBee receiving apparatus according to an embodiment.
7 is a flowchart of a method of generating a ZigBee packet performed by a ZigBee transmission apparatus according to another embodiment.
8 is a flowchart of a ZigBee detection method performed by a ZigBee receiving apparatus according to another embodiment.

The details of other embodiments are included in the detailed description and drawings. Advantages and features of the described technology, and how to achieve them, will become apparent with reference to the embodiments described below in detail in conjunction with the drawings. Like reference numerals refer to like elements throughout.

Hereinafter, embodiments of a ZigBee detection method and a ZigBee device in a heterogeneous wireless network will be described in detail with reference to the drawings.

1 illustrates an operation of a general ZigBee system in a heterogeneous wireless network.

A typical ZigBee system as shown in FIG. 1 employs a duty cycling mechanism to minimize energy consumption according to idle listening. In duty cycling, each ZigBee device 110 and 120 reduces an idle listening time by repeating a predetermined wakeup/sleep state. The duty cycling-based MAC protocol is divided into a synchronous (synchronous) and an asynchronous (asynchronous) scheme. In this case, the asynchronous duty cycling is based on a Low Power Listening (LPL) scheme.

Referring to FIG. 1 , when there is interference (I) of another wireless device 130 when the ZigBee transmitting device 110 and the ZigBee receiving device 120 exchange data packets according to the duty-cycling mechanism, the ZigBee receiving device (120) A malfunction occurs.

For example, if there is data to be transmitted, the ZigBee transmitting device 110 initiates a transmission procedure of continuously transmitting data packets until an ACK is received from the intended ZigBee receiving device 120 . At this time, if the time limit such as the channel polling interval is exceeded, the ZigBee transmitting apparatus 110 transmits data at the next opportunity.

The ZigBee receiving device 120 periodically wakes up and checks the media status based on the CCA (Clear Channel Assessment) method defined in IEEE 802.15.4. That is, the ZigBee receiving device 120 measures the energy level of the media and determines whether to receive data or to enter the sleep state. However, if the interference (I) by the other wireless device 130 generates an energy level higher than the channel evaluation threshold of the idle media, the ZigBee receiving device 120 unnecessarily wakes up and enters an idle listening state, which does not exist. It waits for the next data packet. Due to this, the ZigBee receiving device 120 generates unnecessary energy loss.

2 illustrates an operation of a ZigBee system according to an embodiment in an interference environment of heterogeneous wireless networks.

Referring to FIG. 2 , the ZigBee system according to an embodiment can prevent the device from entering the idle listening state by directly entering the sleep state even when interference by the heterogeneous wireless device 230 occurs.

For example, the ZigBee transmission device 210 may transmit a data packet by inserting a predefined ZigBee signature. In this case, the ZigBee signature indicates ZigBee transmission to be processed by the ZigBee receiving device 220 . The ZigBee signature may be inserted in a pre-reserved field before the preamble of the data packet.

The ZigBee receiving device 220 according to an embodiment transmits signals received in a heterogeneous wireless network environment by using a ZigBee detection technique (CoSense) implemented to efficiently detect ZigBee transmission. It can be determined whether it is a data packet. At this time, as will be described in detail later, the ZigBee detection technique (CoSense) according to the present embodiment is received using a channel assessment technique, a signal correlation technique, etc. based on Received Signal Strength Indication (RSSI). It is possible to determine whether the signals are ZigBee transmission or interference (I) by a heterogeneous wireless device 230 .

That is, the ZigBee receiving device 220 periodically switches to the wake-up state at every duty cycle interval, and when interference I is generated by the heterogeneous wireless device 230, it is determined whether ZigBee transmission is performed. At this time, since the interference (I) is not ZigBee transmission, it can immediately switch to the sleep state without switching to the idle listening state. Accordingly, the waiting time in the idle listening state may be reduced, and thus energy consumption of the ZigBee receiving apparatus 220 may be reduced.

3 is a block diagram of an apparatus for transmitting ZigBee according to an embodiment.

Referring to FIG. 3 , the ZigBee transmitting apparatus 300 may include an interference determining unit 310 , a packet generating unit 320 , and a packet transmitting unit 330 .

The interference determination unit 310 may determine whether interference exists in a heterogeneous wireless network environment. In this case, if it is determined that interference exists, the strength of the interference, that is, the signal strength generated from different types of wireless devices generating the interference may be measured. Here, the interference determination unit 310 may be omitted if necessary.

The packet generator 320 generates a data packet when there is data to be transmitted. In this case, the data packet may be generated according to IEEE 802.15.4, but is not particularly limited thereto.

According to an embodiment, the data packet may include a reserved field of a predetermined bit size for inserting a ZigBee signature in front of a preamble. In this case, the pre-reserved field may include a ZigBee signature field of up to 7 bits and a dummy field of 1 bit indicating the ZigBee signature.

When generating a packet for data to be transmitted, the packet generator 320 may insert a predefined ZigBee signature into the data packet. In this case, the ZigBee signature may be a predefined 7-bit pseudo-random noise (PN) sequence.

In this case, according to an embodiment, the packet generation unit 320 may determine whether to insert the ZigBee signature based on the determination result of the interference determination unit 310, and when determining to insert the ZigBee signature, the size of the ZigBee signature may be determined. .

As an example, when the interference determining unit 310 determines that there is no interference from nearby heterogeneous wireless devices, the packet generating unit 320 may not insert the ZigBee signature into the data packet.

As another example, when the interference determination unit 310 determines that there is interference from nearby heterogeneous wireless devices and measures the interference strength of the interfering devices, the size of the ZigBee signature to be inserted into the data packet is determined based on the interference strength. can decide That is, it is possible to insert a predefined 1-bit ZigBee signature when the interference strength is very weak, and insert a predefined 7-bit ZigBee signature when the interference strength is very strong. In this way, the packet generator 320 may insert a predefined ZigBee signature of 1 bit to 7 bits into the ZigBee signature field according to the strength of the interference.

The packet transmitter 330 transmits the generated data packet to the ZigBee receiver. In this case, continuous data packets may be transmitted until an ACK is received from the ZigBee receiving device.

4 is a block diagram of a ZigBee receiving apparatus according to an embodiment.

Referring to FIG. 4 , the ZigBee receiving apparatus 400 may include a ZigBee transceiver 410 , a channel state evaluator 420 , a ZigBee signature checker 430 , and a duty cycle controller 440 .

The ZigBee transceiver 410 is turned on by the duty cycle controller 440 to enter a wake-up state, and receives various signals including a ZigBee signal. In this case, the ZigBee transceiver 410 may be an RF transceiver.

The channel state evaluator 420 may evaluate whether the channel state is an idle state or a busy state based on the RSSI.

For example, the channel state evaluator 420 includes an RSSI sampler that collects a series of RSSI samples from the RSSI register of the ZigBee transceiver 410 and a channel evaluator that processes the series of RSSI samples to evaluate the channel state ( channel estimator). The channel evaluator may return a value indicating that the channel is in an idle state if the RSSI value of processing the series of RSSI samples is lower than a preset channel evaluation threshold, and otherwise may return a value indicating that the channel is in a busy state.

The ZigBee signature check unit 430 may check whether a ZigBee signature exists in the received signal.

For example, the ZigBee signature checker 430 transmits ZigBee by correlating the ZigBee signature with a signal sampler that collects raw samples of the signal, and the collected raw samples with a predefined ZigBee signature. It may include a feature detector for checking the existence of.

In this case, the ZigBee signature checker 430 may check whether the ZigBee signature exists by applying a signal correlation technique as in Equation 1 below. Equation 1 is an equation obtained by calculating a correlation at a shift position delta (Δ) with respect to symbol sequences of a predefined length L.

Here, the sample (s[k], 1≤k≤L) represents a predefined symbol, and s ^* [k] represents a complex conjugate.

At this time, when the received ZigBee signature is perfectly aligned to the beginning of s, the correlation value soars. That is, when the correlation value is greater than or equal to the correlation threshold, the ZigBee signature check unit 430 may recognize that the ZigBee signature exists.

The duty cycle controller 440 may turn on/off the power of the ZigBee transceiver 410 based on at least one of the evaluated channel state and the existence of the ZigBee signature to switch to the next state. For example, the duty cycle control unit 440 determines whether the received signal is ZigBee transmission based on the state of the channel and the existence of the ZigBee signature, and when it is determined that the received signal is ZigBee transmission, the power of the ZigBee transceiver 410 is kept on The ZigBee transceiver 410 may be switched to the listening state, otherwise the ZigBee transceiver 410 may be turned off to put the ZigBee transceiver 410 into a sleep state.

According to an example, the duty cycle controller 440 may determine that the received signal is ZigBee transmission when the channel state is the busy state and the ZigBee signature is present. In this way, the duty cycle controller 440 checks the existence of a ZigBee signature by applying a correlation technique as well as a channel state evaluated based on RSSI, so that even if interference from a heterogeneous wireless device having a large RSSI occurs, the idle listening state is maintained. It is possible to immediately switch to the sleep state without waiting.

According to another example, the duty cycle controller 440 may determine whether the heterogeneous wireless device has interference, and if there is no interference from the heterogeneous wireless device, the channel state is busy without considering the existence of the ZigBee signature. You can immediately switch to the listening state.

5 is a flowchart of a method for generating a ZigBee packet performed by a ZigBee transmission apparatus according to an embodiment.

Referring to FIG. 5 , when there is data to be transmitted, the ZigBee transmission apparatus may insert a predefined ZigBee signature into the data packet ( 510 ). In this case, the ZigBee data packet may be generated according to IEEE 802.15.4, and may include a field reserved in advance for insertion of the ZigBee signature in front of the preamble. In this case, the reserved field may include a 7-bit ZigBee signature field and a 1-bit dummy field. In the 7-bit ZigBee field, a maximum of 7 indicating a predefined ZigBee signature to be shared among ZigBee devices in a heterogeneous wireless network environment. A PN sequence of bits may be inserted.

Then, the generated data packet is transmitted to the ZigBee receiving apparatus ( 520 ).

6 is a flowchart of a ZigBee detection method performed by a ZigBee receiving apparatus according to an embodiment.

Referring to FIG. 6 , the ZigBee receiving device periodically wakes up in units of duty cycle and switches to the wake-up state ( 610 ).

Then, the state of the channel is evaluated based on the RSSI ( 620 ). In this case, a clear channel assessment (CCA) technique may be utilized. The ZigBee receiving device may collect RSSI samples from the RSSI register of the ZigBee transceiver in the wake-up state, and process a series of collected samples to evaluate the channel state. The ZigBee receiving device returns a value indicating that the channel is in an idle state if the RSSI value is lower than a preset channel evaluation threshold as a result of the processing, otherwise it may return a value indicating that the channel is in a busy state. .

Thereafter, it may be checked whether a ZigBee signature is present in the received signals ( 630 ). The ZigBee signature may be inserted before the preamble of the data packet by the ZigBee transmission device. At this time, a predefined ZigBee signature exists in the reserved field by using a signal correlation technique that collects a raw sample of the signal and correlates the collected raw sample with the PN sequence of a previously reserved field in the received signal. can determine whether In this case, it is possible to determine whether a ZigBee signature exists by calculating a signal correlation value by the signal correlation function as in Equation 1, and comparing the calculated signal correlation value with a predefined threshold.

Next, it is determined whether the channel state evaluated in the channel evaluation step 620 is a busy state ( 640 ), and if it is not the busy state, the ZigBee transceiver is turned off, thereby entering an idle listening state and waiting for the next packet. Instead, it may immediately switch to the sleep state (670).

At this time, if the channel state is busy, it is checked whether it is determined that the ZigBee signature is present in step 630 ( 650 ). It may switch to a listening state for receiving ( 660 ). At this time, if it is determined that the ZigBee signature does not exist in the received signal in step 650, it can immediately switch to the sleep state without waiting in the idle listening state (670).

In this way, even if the RSSI value is greater than or equal to the predefined channel evaluation threshold, the existence of the ZigBee signature is also considered, so there is no need to unnecessarily wait in the idle listening state even when the RSSI due to interference is above the channel evaluation threshold, thereby reducing power consumption. can

7 is a flowchart of a method of generating a ZigBee packet performed by a ZigBee transmission apparatus according to another embodiment.

Referring to FIG. 7 , when there is data to be transmitted, the ZigBee transmission apparatus may determine whether there is interference from a nearby heterogeneous wireless device before generating a data packet ( 710 ).

As a result of the determination (710), if there is no interference from nearby heterogeneous wireless devices (720), the data packet is directly generated (760) without inserting the ZigBee signature into the data packet, and the generated data packet is transmitted to the ZigBee receiving device (770). can send

As a result of the determination 710 , if there is interference from a nearby heterogeneous wireless device ( 720 ), the intensity of the interference may be measured ( 730 ).

Next, a size of the ZigBee signature to be inserted into the data packet may be determined based on the measured interference strength ( 740 ). In this case, the ZigBee signatures to be inserted may be predefined in size from 1 bit to 7 bits according to the interference strength.

Thereafter, a data packet to be transmitted may be generated by inserting a ZigBee signature corresponding to the determined size into the data packet ( S750 ). In this case, an area of 8 bits before the preamble of the data packet may be reserved in advance as a field for inserting a ZigBee signature indicating that the ZigBee data packet is transmitted. In this case, 7 bits among 8 bits may be a ZigBee field for inserting a ZigBee signature, and 1 bit may be a dummy field.

Thereafter, the generated data packet may be transmitted to the ZigBee receiving apparatus ( 770 ). In this case, it is possible to continuously transmit until an ACK is received from the ZigBee receiving device.

According to the disclosed embodiment, the ZigBee transmitting apparatus determines whether to insert the ZigBee signature in consideration of the interference and the strength of the interference of the neighboring heterogeneous wireless devices, thereby reducing the overhead caused by inserting the ZigBee signature into each data packet. can do it

8 is a flowchart of a ZigBee detection method performed by a ZigBee receiving apparatus according to another embodiment.

Referring to FIG. 8 , the ZigBee receiving device periodically wakes up every duty cycle and switches to a wakeup state ( 810 ).

Then, the state of the channel may be evaluated based on the RSSI ( 820 ). For example, RSSI samples may be collected from the RSSI register of the ZigBee transceiver, and a channel state may be evaluated as a busy state or an idle state by processing the collected RSSI samples.

Thereafter, it may be checked whether a ZigBee signature is present in the received signal ( 830 ). For example, it is possible to determine whether a ZigBee signature exists in a reserved field position in a received signal by using a signal correlation technique as in Equation 1. In this case, when the PN sequence inserted into the 7-bit region reserved in advance in the data packet and the raw sample of the collected signal are signal-correlated, when the correlation value is equal to or greater than a threshold, it can be determined that the ZigBee signature is present.

Next, it is determined whether the channel state evaluated in step 820 is a busy state ( 840 ), and if it is not a busy state, it immediately switches to a sleep state ( 880 ), and if it is a busy state, it is determined whether there is interference from heterogeneous wireless devices may (850).

At this time, if there is interference from heterogeneous wireless devices (850), the determination result of whether or not the ZigBee signature is present is checked in step 830, and if the ZigBee signature is present (860), it switches to the listening state (870), Otherwise, it may transition to a sleep state (880).

If there is no interference from heterogeneous wireless devices ( 850 ), the listening state may be directly switched to the listening state without checking whether the ZigBee signature is present ( 870 ).

In addition, if it is confirmed in step 860 that the ZigBee signature does not exist, the sleep state may be immediately switched to the sleep state (880).

As described above in detail, the above-described embodiments may be applied to a sender initiated rendezvous mechanism. Accordingly, the ZigBee devices can efficiently reduce power consumption by minimizing unnecessary idle listening states by checking whether or not ZigBee transmission is present. However, it is apparent that the present invention is not limited to the above-described embodiments and can be applied to a receiver initiated rendezvous mechanism.

For example, in the receiver-driven rendezvous mechanism, in general, a ZigBee receiving device first transmits a probing packet to a potential ZigBee transmitting device. At this time, if the probing packet is interrupted by interference, the intended ZigBee transmission device waits for the probing packet, which causes significant power consumption. In addition, decoding the probe packet by the ZigBee transmitter is more susceptible to interference than the CCA technique, and thus the ZigBee transmitter loses a transmission opportunity.

Therefore, as described above, the ZigBee receiving device inserts a predefined ZigBee signature into the probing packet to be transmitted, and the ZigBee transmitting device detects the probing packet by checking the ZigBee signature without having to decode the received packet. do.

Those of ordinary skill in the art to which the present disclosure pertains will understand that it may be implemented in other specific forms without changing the disclosed technical spirit or essential features. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

300: Zigbee transmitter 310: Interference determining unit
320: packet generator 330: packet transmitter
400: Zigbee receiving device 410: Zigbee transceiver
420: channel state evaluation unit 430: Zigbee signature check unit
440: duty cycle control

Claims (18)

an interference determination unit that determines whether there is interference from a nearby heterogeneous wireless device, and measures the intensity of the interference if there is interference from the adjacent heterogeneous wireless device;
a packet generator for generating a data packet by inserting a predefined ZigBee signature based on the measured interference strength; and
Including; a packet transmitter for transmitting the generated data packet;
The packet generator
When it is determined by the interference determination unit that interference of the heterogeneous wireless device exists, a size of a ZigBee signature is determined based on the measured interference strength, and a predefined ZigBee signature corresponding to the determined size is inserted. Zigbee transmitter in a wireless network. delete According to claim 1,
The packet generator
As a result of the determination of the interference determination unit, if there is no interference from heterogeneous wireless devices, the ZigBee transmission apparatus does not insert the ZigBee signature. delete According to claim 1,
The data packet includes a 7-bit ZigBee signature field and a 1-bit dummy field for inserting a ZigBee signature before a preamble. a channel state estimator for evaluating a state of a channel based on RSSI in a wakeup state;
a ZigBee signature checker for checking whether a ZigBee signature exists in the signal received in the wake-up state; and
a duty cycle control unit for controlling transition to a next state based on at least one of the channel state and the existence of the ZigBee signature;
The ZigBee signature is composed of a PN (Pseudo-random Noise) sequence of predetermined bits, and is inserted into a pre-reserved field before the preamble signal of the data packet by the ZigBee transmission device;
The size of the predetermined bit is a ZigBee receiving apparatus in a heterogeneous wireless network, characterized in that it has a maximum of 7 bits according to the interference strength of the neighboring heterogeneous wireless devices. 7. The method of claim 6,
The Zigbee signature check unit
A ZigBee receiving apparatus for calculating a correlation value for a predetermined sequence of bits and a predefined sequence of signal samples from the received signal, and checking whether a ZigBee signature exists based on the calculated correlation value. 7. The method of claim 6,
The duty cycle control unit
If the channel state is a busy state and the ZigBee signature exists, switch to a listening state, and otherwise switch to a sleep state. 7. The method of claim 6,
The duty cycle control unit
If there is no interference from neighboring heterogeneous wireless devices, the ZigBee receiving device controls to switch to the listening state when the channel state is the busy state. delete delete converting the ZigBee receiving device to a wakeup state;
evaluating a state of a channel based on the RSSI in a wake-up state;
checking whether a ZigBee signature is present in the received signal; and
switching to the next state based on at least one of the channel state and the existence of the ZigBee signature;
The ZigBee signature consists of a PN (Pseudo-random Noise) sequence of predetermined bits, and is inserted into a pre-reserved field in front of the preamble signal by the ZigBee transmission device,
The size of the predetermined bit has a maximum of 7 bits according to the interference strength of the heterogeneous wireless device. 13. The method of claim 12,
Evaluating the state of the channel comprises:
collecting a series of RSSI samples from the RSSI register; and
A Zigbee detection method comprising: processing a series of collected RSSI samples to evaluate a channel state as an idle state or a busy state. 13. The method of claim 12,
The step of checking the existence of the ZigBee signature is
and calculating a correlation value for a predetermined sequence in the received signal and a predefined sequence of signal samples, and checking whether the ZigBee signature exists based on the calculated correlation value. 13. The method of claim 12,
The step of transitioning to the next state is
A ZigBee detection method for switching to a listening state when the channel state is a busy state and the ZigBee signature exists, and switching to a sleep state otherwise. 13. The method of claim 12,
The step of transitioning to the next state is
A ZigBee detection method for switching to a listening state when the channel state is a busy state when there is no interference from nearby heterogeneous wireless devices. delete delete

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